From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 622932F1FC3 for ; Thu, 20 Aug 2026 09:53:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787219641; cv=none; b=C+QMlc7qe3qblcBB3nCF6uX7s9uShN3GN34R/qbdeWUEur/9MsPO34Dyk7JWghHf9z/4D8fTw+l2k40N/JGOXMHsUIpv17j0VzI14NpjCb6vK4+YnIqvEmB84Gf1uQUMb3h/uNRuO2ghPhZW8cByduRupsiPZNRwmBtV3pCNRjc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787219641; c=relaxed/simple; bh=PmQiZHk4AuQPbLXMPxz7hLIM4nOoWbZdRw/umlr2KRU=; h=From:To:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=mx+Yx2s/0/+qb4/KjrY4h77iMz/L3CmrCgCxuoPuQrmTFcWt/A6/sLuXIJuNE39BNYba+IKxQ9OYMM6FAFfnKW4l5BiVx7pGys9rm/llO6YJ3l5dksLLl7S2AE550NQNg+j856p0+OG30eUTLXejUGCwv5MqXfCbw4Q7loeL1VI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=jYW049LI; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=5XOlJhx0; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="jYW049LI"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="5XOlJhx0" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1787219637; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=PmQiZHk4AuQPbLXMPxz7hLIM4nOoWbZdRw/umlr2KRU=; b=jYW049LIdUCumOSI/mSV6BLuHP/LFomNEUWDgJc8ESJN8s+ohMncw1guiKsypjGgOdnsJn lf7V+6jGlNXt0zZ9eFHk+th1/+TG6HiM9zICz/HdSdcXy0qv7L8MetouuY9gXSYIdiXbvl /WLvueswulLe1gH3e4c4CCYUlqBkly51dXt9ulhN5ulE09pVcINq6Ap3wtWaG5Q9KxB9+5 r76RFhfFUwU4zsUFvCPKH53w3Fo9+5q63XS7HnWdHvYkOoFtltcTzlGJPCmioir1h6umtJ eItpG8TJWzVgbLnHwDNOZfj7Tt0/uCNhIiZNTYqqYUYMGDgs0KtYqTc1wzR8zw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1787219637; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=PmQiZHk4AuQPbLXMPxz7hLIM4nOoWbZdRw/umlr2KRU=; b=5XOlJhx0sTreIF/Ihlau7vMkTi75bCfbZ5rV/09WBiJojnXWMYX20aloPiaF9Q7Wki4twY CBfWrKvV+4RI2FAA== To: Tetsuo Handa , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Thomas Gleixner , LKML Subject: Re: [PATCH] printk: Don't WARN on kthread_run failure. In-Reply-To: <76bb4c1c-5d85-4635-b3bb-fc06f292c59e@I-love.SAKURA.ne.jp> References: <76bb4c1c-5d85-4635-b3bb-fc06f292c59e@I-love.SAKURA.ne.jp> Date: Thu, 20 Aug 2026 11:58:32 +0206 Message-ID: <87ik559l0f.fsf@jogness.linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On 2026-08-04, Tetsuo Handa wrote: > Since __kthread_create_on_node() returns -EINTR upon SIGKILL, > we should not use WARN_ON() in order to catch kthread_run() failure. For historical context, the WARN_ON() was suggested here [0]. But since a kthread_run() failure also prints a dedicated failure message, the WARN_ON is overkill. > Reported-by: syzbot+1ebbc20f223b99446034@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=1ebbc20f223b99446034 > Fixes: 5f53ca3ff83b ("printk: Implement legacy printer kthread for PREEMPT_RT") > Fixes: 76f258bf3f2a ("printk: nbcon: Introduce printer kthreads") > Signed-off-by: Tetsuo Handa Reviewed-by: John Ogness [0] https://lore.kernel.org/lkml/87ed95j8yh.fsf@jogness.linutronix.de